Development of a foot and ankle strengthening program for the treatment of plantar heel pain: a Delphi consensus study

BACKGROUND: People with plantar heel pain (PHP) have reduced foot and ankle muscle function, strength and size, which is frequently treated by muscle strengthening exercises. However, there has been little investigation of what exercises are used and there is no sound evidence base to guide practice. This study aimed to develop a consensus-driven progressive muscle strengthening program for PHP. METHODS: Thirty-eight experts were invited to participate in the study over three rounds. Round 1 was an open-ended questionnaire that provided the core characteristics of progressive strengthening programs designed for three different adult patient types with PHP (younger athletic, overweight middle-aged, older), which were presented as vignettes. In Round 2, experts indicated their agreement to the proposed exercises and training variables. In Round 3, experts were presented with amendments to the exercises based on responses from Round 2 and indicated their agreement to those changes. Consensus was achieved when > 70% of experts agreed. RESULTS: Two experts were ineligible and 12 declined, leaving 24 (67%) who participated in Round 1. Eighteen (75%) completed all three rounds. From Round 1, progressive strengthening programs were developed for the three vignettes, which included 10 different exercises and three training variables (sets / repetitions, weight, and frequency). In Round 2, 68% (n = 17) of exercises and 96% (n = 72) of training variables reached consensus. In Round 3, only exercise changes were presented and 100% of exercises reached consensus. CONCLUSIONS: This study provides three progressive strengthening programs agreed to by experts that can be used in future clinical trials to determine the effectiveness of muscle strengthening for PHP. In addition, clinicians could use the programs as part of a rehabilitation strategy with the caveat that they may change as more research is conducted.